l-365260 and Pancreatic-Neoplasms

The peptide hormone cholecystokinin (CCK) plays an important role in the gastrointestinal tract. The rat pancreatic CCK receptor is a highly glycosylated membrane receptor that is able to bind to plant lectins such as wheat germ agglutinin (WGA) and Ulex europaeus agglutinin (UEA-I).. We used both lectins to block this receptor for studying the pathophysiologic relevance of its oligosaccharide side chains. In the present study we investigated the influence of WGA and UEA-I on CCK-8-induced alpha-amylase secretion of the rat pancreatic tumor cell line AR42J, which expresses both CCK-A and CCK-B receptors.. Under the influence of WGA (25 microg/mL), the alpha-amylase release was reduced by 25% after 30 minutes compared with the hormone-stimulated controls. UEA-I (25 microg/mL) caused a reduction of 20%. The simultaneous application of the lectins with CCK antagonists L 364,718 or L 365,260 led to a reduction of secretion, but the assignment to CCK-A or CCK-B receptors was not possible.. In long-term studies, both lectins revealed no toxic or apoptosis-inducing effects. On the contrary, WGA showed an inhibitory effect on cell proliferation and led to improved differentiation of cells.

Topics: alpha-Amylases; Animals; Benzodiazepinones; Cell Differentiation; Cell Division; Devazepide; Kinetics; Lectins; Microscopy, Electron; Pancreas; Pancreatic Neoplasms; Phenylurea Compounds; Plant Lectins; Rats; Receptor, Cholecystokinin A; Receptor, Cholecystokinin B; Receptors, Cholecystokinin; Sincalide; Tumor Cells, Cultured; Wheat Germ Agglutinins

The role of cholecystokinin (CCK) and gastrin in the development and growth of pancreatic cancer cells is controversial. The aim of this study was to evaluate the role of CCK-8S, gastrin-17, bombesin, and their antagonists on cell lines from patients with pancreatic cancer.. Cell lines were established from pancreatic cancers operated on at our department. The cells were grown in 10% fetal calf serum (FCS). The effects of CCK-8S, gastrin-17, bombesin, and their antagonists in different concentrations and for different time intervals were studied. The cell number was evaluated with the XTT method.. The cell line LN 36 responded with increased cell number to stimulation by gastrin-17 and decreased cell number to inhibition by the CCK-B receptor antagonist L-365,260. In contrast, LPC 1 responded with increased cell number to CCK-8S and decreased cell number to the CCK-A receptor antagonist devazepide. LPC 2, 6, and 7 were stimulated by CCK-8S, gastrin-17, and their antagonists. LPC 3 showed decreased cell number after inhibition by the antagonists, and LPC 5 and 10 showed increased cell number after stimulation by CCK-8S and gastrin-17. LPC 4 was stimulated by CCK-8S, and LPC 8 was stimulated by all substances except gastrin-17. Intermittent administration of the substances to LN 36 led to a greater effect on the cell number than administration every day, which was not the case with LPC 1 and LPC 3. Bombesin led to an increased growth in LPC 5 but not in LPC 3.. CCK-8S and gastrin-17 led to an increased cell number in some cell lines. A blockade of the CCK-A and CCK-B receptors by their antagonists led to an increased, an unaffected, or a decreased cell number of the cell lines. The effect of bombesin on different cell lines also varied. This shows a great heterogenicity among pancreatic cancer cells from different patients.

Topics: Benzodiazepinones; Bombesin; Cell Division; Cholecystokinin; Devazepide; Dose-Response Relationship, Drug; Gastrins; In Vitro Techniques; Pancreatic Neoplasms; Phenylurea Compounds; Receptors, Cholecystokinin; Tumor Cells, Cultured

To examine the effect of gastrin on spontaneous and induced pancreatic carcinogenesis in the hamster.. Two sets of experiments were carried out, one involving long term hypergastrinaemia and one involving cancer induction during hypergastrinaemia. The effect of hypergastrinaemia accomplished by gastric fundectomy was studied for eight months. Neither fundectomised hamsters nor sham operated controls developed premalignant or malignant pancreatic lesions. In the fundectomy group, the mean pancreatic weight, total protein content, and DNA content was increased by 28%, 25%, and 25% respectively. No such increases were found in fundectomised animals receiving a cholecystokinin-B receptor antagonist during the last 24 days of the experiment. In the cancer induction study, the effect of fundectomy on N-nitrosobis(2-oxopropyl) amine induced pancreatic carcinogenesis was studied for three months. There were no significant differences in the incidence or [3H]-thymidine labelling index of focal pancreatic lesions between fundectomised and sham operated control animals.. Fundectomy with chronic hypergastrinaemia induces pancreatic hypertrophy, but does not enhance N-nitrosobis (2-oxopropyl)amine induced pancreatic carcinogenesis in the hamster. The increases in growth were inhibited by a cholecystokinin-B receptor antagonist, indicating that the trophic effect of fundectomy is mediated by gastrin.

Topics: Animals; Benzodiazepinones; Carcinogens; Cholecystokinin; Cricetinae; Disease Models, Animal; Gastric Fundus; Gastrins; Hypertrophy; Male; Mesocricetus; Neoplasms, Experimental; Nitrosamines; Pancreas; Pancreatic Neoplasms; Phenylurea Compounds; Receptors, Cholecystokinin

It was recently found that cholecystokinin (CCK) activates mitogen-activated protein kinases (MAPK) in isolated rat pancreatic acini. The present study evaluates whether one or both types of CCK receptors are capable of MAPK activation in pancreatic AR42J acinar cells as well as CHO cells transfected with CCK-A or CCK-B receptors. CCK significantly increased p44 MAPK and p42 MAPK activities in AR42J cells. Minimal, half-maximal, and maximal responses were observed at 30 and 500 pM and 10 nM, respectively, after CCK-8 stimulation and at 100 pM and 1.5 and 30 nM, respectively, after gastrin stimulation. Glycine-extended gastrin had no effect at 100 nM and a small but significant effect at 1 microM. The CCK-B receptor antagonist L365,260 almost totally blocked MAPK activation in AR42J cells after stimulation with gastrin and glycine-extended gastrin and substantially reduced the activation of both kinases by CCK-8, while the CCK-A receptor antagonist L364,718 was much less effective. The CCK-A-selective agonist A71376, however, was an effective stimulant of MAPK activity. In an alternative approach, stably transfected CHO cells bearing either CCK-A or CCK-B receptors were stimulated with CCK-8. Each receptor induced a time-dependent increase in activity of both MAPKs by five- to sixfold in CCK-A- and CCK-B-bearing cells. In conclusion, both CCK-A and CCK-B receptors activate MAPK in AR42J cells and in transfected CHO cells.

Topics: Animals; Benzodiazepinones; Blotting, Western; Carcinoma, Acinar Cell; Cells, Cultured; CHO Cells; Cricetinae; Devazepide; Dose-Response Relationship, Drug; Gastrins; MAP Kinase Kinase Kinase 4; MAP Kinase Kinase Kinases; Oligopeptides; Pancreatic Neoplasms; Phenylurea Compounds; Protein Kinases; Rats; Receptor, Cholecystokinin A; Receptor, Cholecystokinin B; Receptors, Cholecystokinin; Reference Values; Sincalide; Transfection; Tumor Cells, Cultured

The present study reports the first evidence that the gastrointestinal peptide gastrin stimulates the growth of several human pancreatic cancer cells in culture and in tumors transplanted to nude mice. Gastrin promoted growth of all cell lines tested at a dose comparable to the binding affinity, providing evidence for a physiologically relevant receptor. The stimulatory effects of gastrin were blocked by the CCK-B/gastrin receptor antagonist L-365,260 and not by the CCK-A receptor antagonist L-364,718. Growth of PANC-1 cells in culture were inhibited by L-365,260, suggesting that gastrin is tonically produced by PANC-1 cells for regulation of growth. Athymic nude mice bearing PANC-1 xenografts were treated for 24 days subcutaneously with either 1% bovine serum albumin (diluent), pentagastrin (1 mg/kg), or L-365,260 (1 mg/kg) twice daily. Tumors from the pentagastrin-treated mice were found to weigh more and have greater protein and DNA content than controls, whereas these values were all decreased in tumors of L-365,260-treated mice. Receptor binding capacity changed in tumors of animals treated with the peptide or antagonist, suggesting a regulatory process. Gastrin immunoreactivity was detected in a transplanted PANC-1 human tumor. These results identify gastrin as a potent trophic peptide that actively stimulates growth of human pancreatic cancer and does so through a CCK-B/gastrin-like receptor.

Topics: Animals; Benzodiazepinones; Cell Division; Cell Line; Cholecystokinin; Devazepide; Gastrins; Growth Substances; Humans; Male; Mice; Mice, Nude; Pancreatic Neoplasms; Pentagastrin; Phenylurea Compounds; Receptors, Cholecystokinin; Transplantation, Heterologous; Tumor Cells, Cultured

A selective gastrin receptor (GR) antagonist, L-365,260 is bound to the GR on AR42J cells with a potency 7.5-fold less than G17 (50% inhibitory concentration [IC50] G17, 6 x 10(-9) mol/l; IC50 L365-260, 4.5 x 10(-8) mol/l). G17 is mitogenic for AR42J cells, as assessed by 75Se-selenomethionine uptake and L-365,260 at concentrations of 2.5 x 10(-6) mol/l and 2.5 x 10(-7) mol/l, (55X and 5.5 X the dose required to displace 50% 125I G17, respectively), and reduced optimal G17 stimulated mitogenesis in 75% of experiments. The basal growth of two human colon cancer cell lines, LoVo and C146 was reduced by L-365,260 (2.5 x 10(-7) mol/l) after 5 days of treatment to 44% and 64% of the control, respectively. However, inhibition was followed by a rebound of growth to control levels. The growth of AR42J xenografts in nude mice was increased by administration of G17 (10 micrograms/mouse/d, P less than 0.027). This increase was blocked by coadministration of oral L-365,260 (5 mg/kg/d, P less than 0.034). L-365,260 could be an important therapeutic agent in slowing the growth of GR-positive, G17-sensitive gastrointestinal tumors.

Topics: Adenocarcinoma; Animals; Benzodiazepinones; Colonic Neoplasms; Dose-Response Relationship, Drug; Mice; Mice, Nude; Pancreatic Neoplasms; Phenylurea Compounds; Rats; Tumor Cells, Cultured